There is a conventional image processing device that determines whether an obtained image is a blank image, i.e. solid-color sheet, or a non-blank image. The image processing device includes a scanner unit and a control unit. The scanner unit reads a document sheet to obtain read image data. The control unit divides the read image from the obtained read data into blocks or a plurality of regions that are constant in size. The control unit determines whether each block is a blank block or a non-blank block. If the control unit judges even one of a plurality of blocks as a non-blank block, then the control unit determines that the read image is a non-blank.